The endurance crack is apt to be produced in collar thread during drilling, which eventually results in the connection failure. 在钻井过程中,钻铤螺纹容易产生疲劳裂纹,最终导致连接失效。
Then, because gushing out of lukewarm water under different operating mode, causes endurance crack of header and tube socket's internal surface under repeatedly thermal shock stress. 而后由于减温水和断口处一定时间内不同工况下的喷溢,致使联箱和管座内壁局部表面在反复热冲击应力作用下疲劳开裂。
The probability research of the extending law of the endurance crack for sucker rod material 抽油杆材料疲劳裂纹扩展规律的概率研究
The vital application properties such as high temperture endurance strength, creep limit, fracture toughness at room temperature, creep crack propagation rate of Cr-Mo-V and Cr-Mo high temperature castings for large steam turbines are comparatively studied, thus providing a cue for reasonable selection of materials. 本文对大型汽轮机高温铸件用Cr-Mo-V和Cr-Mo两类铸钢的持久强度、蠕变极限、室温断裂韧性、蠕变裂纹扩展速率等主要应用性能进行了比较研究,为合理选材提供了依据。
Using ultrasonic to inspect endurance crack in collar thread 钻铤螺纹疲劳裂纹的超声波检测
In view of saving resource, energy and of increasing concrete endurance as well as environment protection, the paper describes the necessity of developing green high performance concrete and puts forward the solution to problems of its high production cost and early crack etc. 文章从节约资源、能源、提高砼耐久性及保护环境的角度,阐述了发展绿色高性能砼的必要性,对高性能砼存在的造价高、早期开裂等问题提出了解决办法。